The present invention relates to an electro-optical distance measuring device capable of acquiring an image, and of measuring a distance to an object in the image and a three-dimensional shape of the object.
One of electro-optical distance measuring methods is a method to measure a distance by using a phase measurement. In this electro-optical distance measuring method, a high frequency light signal is irradiated to the object to be measured, a reflected from the object to be measured is converted into an electrical signal, a frequency of the electrical signal is converted to low frequency (i.e., beaten down) by a frequency converter of electronics, and the distance is measured by detecting a low frequency phase.
Feature of the electro-optical distance measuring method is to utilize a property that a high frequency phase is kept as a low frequency phase when the high frequency is down-converted. Thus, high resolution measurement is achieved.
However, for example, for measuring a three-dimensional shape of an object to be measured or for other purposes, it is necessary to measure distances with respect to as many as thousands or more points. In conventional electro-optical distance measuring method, a measurement is made for one point at a time and the measurement is made for each one point sequentially. Therefore, long time is required for the measurement. Or, even if a plurality of measuring devices are used, remarkable improvement cannot be expected in the measuring time.